The potential of restaurant trap grease as biodiesel feedstock

Abstract

The possibility of using restaurant trap grease as feedstock in the production of biodiesel via acid catalyzed esterificationis explored in this study. Sulfuric acid was used as a catalyst for the esterification reaction of free fatty acid (FFA) andmethanol. The FFA levels of restaurant trap greases were reduced from 60.38±2.22 mg KOH/g to 11.60±1.60 mgKOH/g whenconditions for biodiesel production are as follow: methanol-to-FFA ratio of 5:1, 5 wt.% H2SO4, and a reaction temperature at60°C with a reaction time of 60 min. During the acid-catalyzed esterification, the percentage of methyl esters resulting fromconversion of FFA in the obtained product was 83.59±1.51% based on the result of 1H NMR analysis. Data obtained from the23 full factorial designs revealed that methanol-to-FFA ratio term had the most significant effect on the percentage of methylesters, followed by the H2SO4 concentration. Conversely, reaction time between 1 and 3 hours had no significant effect on theesterification of trap greases.

Keywords

• waste greases
• brown grease
• methyl ester
• factorial design
• esterification